Retaining collar



FIG. 1 is a top plan view of a retaining collar showing our new design, the bottom plan, left side elevation, and right side elevation views being identical thereto;

FIG. 2 is a cross-sectional view thereof;

FIG. 3 is a front perspective view thereof;

FIG. 4 is a front elevation view thereof; and,

FIG. 5 is another cross-sectional view thereof, shown in an environment of use with an applicator, syringe or the like.

Views of the retaining collar that are not shown in the drawings form no part of the claimed design.

The broken line showing of the applicator, syringe or the like in FIG. 5 is for the purpose of illustrating environmental structure that forms no part of the claimed design. 

CLAIM The ornamental design for a retaining collar, as shown and described. 